According to the Daily Beast, Google Instant does not want the word 'lesbian'. This word, like the word 'Latina', is blocked.
“The algorithms we use to remove a prediction from autocomplete consider a variety of factors. Among other things, we exclude predictions for queries when the query itself appears to be pornographic, violent or hateful. ... Importantly, we also consider the search results themselves for given queries. So, if the results for a particular query seem pornographic, our algorithms may remove that query from autocomplete even if the query itself wouldn't otherwise violate our policies.”
Gawker says "none of the first page of results for 'lesbian' are pornographic, unless you have a very jaded view of the syndicated television series Xena:. Warrior Princess"
Of course, the process has not blocked the word 'dyke'. Yes, proud lesbians use it but Google allows it for proud lesbians or for the hateful meaning?